Indexing machines have been in existence for many years. In Warner U.S. Pat. No. 3,156,037, there is disclosed an indexing machine which has been marketed successfully for a number of years by the assignee of the present invention. Despite the commercial success of the indexing machine of the Warner patent, the machine has room for improvement. For instance, the prior indexing machine employs a ratchet mechanism to control the increments of rotation of a rotatable work support assembly. Because the ratchet mechanism is positioned intermediate the ends of the work support assembly, the work support assembly must be substantially disassembled in order to remove the ratchet mechanism for replacement purposes. Accordingly, ratchet mechanism replacement operations can be time-consuming and costly, due to machine downtime.
In the prior indexing machine, a chuck is utilized to releasably clamp one end of an armature shaft. The chuck is moved by a pneumatic cylinder between a closed position in which the chuck grips the armature shaft and an open position in which the chuck releases the armature shaft. It has been found that the pneumatic cylinder sometimes fails to completely move the chuck from its closed position to its open position, thereby preventing the removal of the armature shaft from the chuck without manual assistance.